var loadChain = new Array();
function onLoad() {
  for (var i=0;i<loadChain.length;i++)
    loadChain[i]();
}
function onLoadAdd(f) {
  loadChain[loadChain.length]=f;
  window.onload = onLoad;
}

function Rotator(config)
{
  this.cur = 1;
  this.hooks = {'fst':-2,'lst':+2,'nxt':+1,'prv':-1,'run':3};
  this.inv = config['interval']*1000;
  this.lim = config['count'];
  this.lnk = config['link'];
  this.nvg = config['nav'];
  this.pfx = config['prefix'];
  this.tic = 0;
  this.run = this.inv? config['run'] : 0;
  this.sld = config['slides'];
  this.typ = config['sequence'];
  var seq  = [];
  for(var i=2;i<=this.lim;i++)
    seq[i-2] = i;
  switch(this.typ) {
    case 'R':
      seq.unshift(1);
      seq=this.shuffle(seq);
      break;
    case 'r':
      seq=this.shuffle(seq);
    default:
      seq.unshift(1);
    }
  seq.unshift(0);
  this.seq = seq;
};
Rotator.prototype.auto = function()
{
  if (this.run!=0) {
    clearTimeout(this.tic);
    this.run=0;
    }
  else {
    this.run=1;
    this.step(0,this.cur);
    }
  this.toggle();
};
Rotator.prototype.bnd  = function(n)
{ 
  if (n<1) n = this.lim;
  else if (n>this.lim) n = 1;
  return n;
};
Rotator.prototype.flip = function(item,state)
{
  for (var i = 0; i < this.pfx.length; i++) {
     var id=this.pfx[i]+item;
     var elm=document.getElementById(id);
     if (elm!=null) elm.style.display = state? 'block' : 'none';
     }
};
Rotator.prototype.hook = function(sfx)
{
  var rotator = this;
  var id=this.lnk+sfx;
  var elm=document.getElementById(id);
  if (elm!=null)
    elm.onclick=function(e) {return rotator.nav(rotator,sfx);};
};
Rotator.prototype.init = function()
{
  if (this.lnk!='')
    for(key in this.hooks)
      this.hook(key);
  if (this.typ=='R')
    this.flip(1,0);
  this.flip(this.seq[1],1);
  this.toggle();
  if (this.run!=0)
    this.step(0,1);
};
Rotator.prototype.nav = function(r,s)
{
  if (r.hooks[s]==3)
    r.auto();
  else if (this.run!=0)
    ;
  else {
    var delta;
    var next;
    switch(delta=r.hooks[s]) {
      case -2:  next=1;         break;
      case +2:  next=this.lim;  break;
      default:  next=r.cur+delta;
      }
    r.step(r.cur,r.bnd(next));
    }
  return false;
};
Rotator.prototype.rotate = function(cur)
{
  this.step(cur,this.bnd(cur+1));
};
Rotator.prototype.shuffle = function(v)
{
  for(var j, x, i = v.length; i; j = parseInt(Math.random() * i), x = v[--i], v[i] = v[j], v[j] = x);
  return v;
};
Rotator.prototype.step = function(cur,next)
{
  if (cur)
    this.flip(this.seq[cur],0);
  this.flip(this.seq[next],1);
  this.cur = next;
  if (this.run!=0 && this.inv>0) {
    var rotator = this;
    this.tic = setTimeout(function() {rotator.timeout(rotator,next);},this.inv);
    }
};
Rotator.prototype.timeout  = function(rotator,cur)
{
  rotator.rotate(cur);
};
Rotator.prototype.toggle   = function()
{
  for(key in this.hooks) {
    var id = this.lnk+key;
    var elm = document.getElementById(id);
    var tgl = key=='run'? this.sld : this.nvg;
    if (tgl==undefined) continue;
    var action = tgl.split(':');
    var value  = action[this.run!=0? 1 : 2];
      if (elm!=null)
        switch(action[0]) {
          case 'class':
            elm.className=value;          break;
          case 'disabled':
            elm.disabled=value;           break;
          case 'display':
            elm.style.display=value;      break;
          default:
            return;
          }
      }
};
Rotator.prototype.toString = function()
{
  var dump = '';
  for(var item in this) {
     if (item=='hooks')
         ;
     else if (typeof this[item]=='function')
         ;
     else dump += item+': '+this[item]+"\n";
     }
  return dump;
};
var rotator_args = {"interval":5,
"link":"p_",
"nav":"display:none:block",
"prefix":['p'],
"run":0,
"count":10};
var rotator = new Rotator(rotator_args);
onLoadAdd(function(){rotator.init();});